The opening line of the first Mishna of Massechet Eruvin (Eruvin 1:1, 2a) informs us that an קורה (cross-beam), which has been placed across the entrance of a מבוי (an alleyway coming off a public domain and leading to a residential area) to permit carrying in that area at a height greater than 20 amot (approx. 10 metres), must be lowered so that it is below 20 amot.
However, as the Gemara immediately points out, this solution-oriented approach of this Mishna differs greatly in language and tone with the first Mishna in Massechet Sukkah (Sukkah 1:1, 2a) where we are told that a Sukkah [whose ‘schach’ is] higher than 20 amot is invalid (פסולה). As the Gemara asks: ‘What is the difference between the laws of Sukkah where an emphatic ‘invalid’ statement is made [with reference to a Sukkah built over 20 amot – notwithstanding the fact that if the Sukkah would be lowered it would be valid], and the laws of the מבוי where the Mishna [did not make an absolute pronouncement and simply] told us how to halachically fix [the מבוי by lowering the קורה]?’
To this, the Gemara offers two answers: 1) Either this difference is because the Sukkah is a biblical law, while the requirement for a קורה at the entrance of a מבוי is a rabbinic requirement, and thus the Mishna was stricter in the former, and more lenient in the latter. 2) Alternatively, it is because the laws of Sukkah are complex and contain many more halachic variables, and consequently, the Mishna chose to be absolute while addressing this particular law. In contrast, the law of the מבוי is not inherently complex, and given this, the Mishna simply specified the fix that was required to render the מבוי valid and thereby permit carrying in that area.
Like these laws of the מבוי and of the Sukkah which address a halachically improper detail and respond with different language and tone given the severity or complexity of the situation, there are times in life when we say or do things, or when things are said or done to us, which are improper to which the appropriate response should differ based on the circumstances.
Sometimes a response might use language and tone that is לשון תיקון (i.e. that is solution-oriented and focusses on the fix), and sometimes it might use language and tone that is לשון פסול (i.e. that is emphatic that focusses on the flaw).
Yet while there are times in our lives – when dealing with the most severe and complex of situations comparable to that of a Sukkah – when לשון פסול is critically necessary to avoid any ambiguity, most of the situations that we find ourselves in are less severe and not so complex, and given this, like this first Mishna in Massechet Eruvin, we should choose to be solution-oriented and use לשון תיקון that focuses on how we can repair and fix relationships – or other problems – that may arise in our lives.